As it is well known, as the circuit density of electronic chip devices increases in order to achieve faster and faster processing speeds, there is a correspondingly increasing demand for the removal of heat generated by these devices. The increased heat demand arises both because the circuit devices are packed more closely together and because the circuits themselves are operated at increasingly higher clock frequencies. Nonetheless, it is also known that runaway thermal conditions and excessive heat generated by chips is a leading cause of failure of chip devices. Furthermore, it is anticipated that demand for heat removal from these devices will increase indefinitely. Accordingly, it is seen that there is a large and significant need to provide useful cooling mechanisms for electronic circuit devices.
Each new generation of computers continues to offer increased speed and function. In most cases, this has been accomplished by a combination of increased power dissipation and increased packaging density. The net result has been increased heat flux at all levels of packaging. For example, one packaging configuration for certain large computer systems today is a multi-blade server system, with each blade containing one or more processor modules along with associated electronics, such as memory, power and hard drive devices. These blades are removable units so that in the event of failure of an individual blade, the blade may be removed and replaced in the field. One problem with this configuration is that the increase in heat flux at the blade level makes it increasingly difficult to dissipate heat by simple air cooling.
Further, in certain data center equipment, a rack containing blade server systems may house several hundred or more microprocessors, which sharply increases the heat dissipation requirements. These systems place an enormous burden on the facility air conditioning system, since all rack or blade server heat is conventionally dissipated into the room ambient air. These air cooled structures are becoming limited in their thermal performance capability by the modest amount of air flow available for cooling. In addition to this restriction, with projected per rack heat loads to exceed 25 kW in the near future, the burden on the facility air conditioning is very high. Thus, an alternative to the state of the art air cooling is desirable.